Chinese crested tern  (Sterna bernsteini)

Previously thought to be possibly extinct, the Chinese crested tern was rediscovered in 2000 with a population of just four adult pairs and four chicks (4). This largish, slender bird has a diagnostic black-tipped yellow bill, sometimes with a tiny white spot at the extreme tip (5). Breeding adults have a white head and black crested cap (5). Underparts are white and upper parts are a pale pearl-grey, with blackish outer primary flight feathers (4) (5). The tail is white and deeply forked, and the legs and feet are black. The non-breeding adult is similar, except that the crown is mottled black and white, merging into the black nape. Juveniles are a mottled brown colour on upper parts, with a paler inner part of the wing lining and two dark bars on the inner wing (5).